Tuesday, December 30, 2008

Happy New Year - 2009

Let us pray for the Peace, Happiness and Prosperity throughout the World. Let God decorate every ray of the sun reaching you with the fragrance of success and prosperity for you. Keep smiling and rocking in 2K9. Wish you a “Very Happy New Year” Dr. Rayat

Monday, December 29, 2008

How Hypertension Is Related To Kidney

High blood pressure or hypertension is one of the most characteristic phenomenon of chronic glomerulonephritis. It is evident that renal lesions (pathological abnormality in kidney) of an ischemic kidney (kidney with poor blood supply) may cause hypertension. This has been seen in the secondary hypertension which develops in the course of glomerulonephritis. Mechanical as well as pathological compression of renal parenchyma has been found to cause hypertension in experimental animals. Chronic pyelonephritis may also cause hypertension.

A variety of renal disorders (kidney diseases) may give rise to hypertension. The kidney disease may be parenchymal or of vascular origin primarily. Morbid anatomical studies have revealed that partial occluding of even one of the renal arteries due to intimal thickening (thickening of internal lining of artery) could be a cause of hypertension due to renal involvement. The vascular or presser substance can be formed by an ischemic kidney. Healthy kidneys are capable of eliminating any presser substance formed in the system. The circulating presser substance is called hypertensin or angiotonin. The angiotonin is formed in the blood by the interaction of an enzyme, renin, secreted by ischemic kidney. The maintenance of normal blood pressure depends on a correct balance between the production of a presser material by the adrenal cortex and its removal by the kidneys. The hypertension may be the result of over-activity of the adrenal gland or some renal disorder.

The primary hypertension and the renal hypertension could be ruled out by the family physician of the patient. In the primary hypertension, the high blood pressure develops early without any renal insufficiency, but in glomerulonephritis, the hypertension develops gradually with renal insufficiency and anemia (fall in hemoglobin level in blood). However, if the patient is seen only after the development of uremia (high level of urea in blood) making distinction between the primary or secondary hypertension could be difficult.

Tuesday, December 23, 2008

What Could Be The Cause Of Swelling On Face

The swelling on face or facial edema should be taken seriously if there is no history of insect bite, wasp sting or honey bee sting and when it is after a throat infection. The swelling on face or facial edema could be due to renal disorder (kidney disease). If on routine examination of urine of the patient, excretion of albumin or protein is detected; there is a need to consult a nephrologist for proper investigations. Blood biochemistry for blood urea, serum creatinine, serum proteins, serum electrophoresis, urine electrophoresis and 24-hour urinary protein should be done. Excretion of protein in 24-hours through urine will help the physician to assess the loss of proteins and possible course of action. Urine electrophoresis would show the type of protein being excreted in the urine. In a patient with nephrotic syndrome, serum electrophoresis would show hypoalbuminemia (low level of albumin in blood), hypogammaglobulinemia (low level of globulins in blood) and raised alpha-2 (a-2) globulin, and urine electrophoresis may show albuminuria (excretion of albumin in urine) or non-selective proteinuria (excretion of almost all the fractions of serum proteins in urine). Total serum protein and its fractions like albumin and globulin would show the altered albumin-globulin ratio. The normal albumin-globulin ratio (Albumin/Globulin) is 3:1 and it may be reversed in patients with swelling on face due to kidney disease.

The swelling on face or facial edema is directly associated with albuminuria (excretion of albumin in urine) and salt retention. The loss of blood albumin through urine hinders the return of fluid from the tissues into the blood and may thus lead to development of edema. It is well known that 68 to 70% weight of our body is due to water content in the blood and tissues. Around 12 to 14% of the total water volume of our body is in the blood and the rest is present in the tissues of the body. There is direct correlation between albuminuria (excretion of albumin in urine) and edema. Retention of Chloride is also a common accompaniment of edema. However, there may not be any retention of Chloride in majority of the cases with edema. The edema is perhaps the greatest problem confronting the students of nephrology. Pathological lesions in the kidney need to be evaluated microscopically through renal biopsy examination. Blood urea and serum creatinine may be normal. There may be salt retention without edema and edema without salt retention. The Chloride may collect in watery subcutaneous tissue due to some external factors also without involvement of any renal lesion.

Two forms of swelling on face or facial edema could be recognized and these are called nephritic edema and nephrotic edema. In nephritic edema the protein content of the edema fluid is over 1 gram/dl whereas in nephrotic edema the protein content of the edema fluid is always less than 0.1 gram/dl. Nephritic edema occurs in acute glomerulonephritis. The capillaries in the subcutaneous tissue become more permeable leading to leakage of proteins in the extra cellular fluid. Nephrotic edema occurs in the wet nephritis or second stage of nephritis, in nephrosis and also in renal amyloidosis. The edema is caused due to the great fall in the osmotic pressure of the blood due to constant loss of protein in urine; so, the fluid from the blood vessels escapes into the tissues in an effort to correct the viscosity of blood plasma.

Monday, December 15, 2008

How Electrolyte Imbalance Causes Renal Disease Or Renal Disease Leads To Electrolyte Imbalance

Electrolytes or essential ions should always be in the state of homoeostasis. The Normal or standard range of electrolytes reflects the normal functional status of our kidneys. Our kidneys play a vital role in preserving the internal environment while excreting the waste products of metabolism, extra water and electrolytes. There is two way selectivity between the cause and effect between the electrolytes (essential ions) and renal disorder (kidney disease). Depletion of Sodium (Na+) or Potassium (K+) or Calcium (Ca++) through excessive urinary excretion may cause renal failure or renal failure may lead to depletion of these ions or electrolytes in the blood plasma.

The renal tubules play a vital role in regulation and preservation of water and electrolytes. The function of tubular epithelium and tubular enzymes is under the control of hormones of some endocrine glands. Suboptimal response of tubular enzymes or over production of corresponding hormone may cause renal disorder (kidney disease). Anti-diuretic hormone of pituitary gland, aldosterone and parathyroid hormone affect the renal tubules to regulate and preserve the water and electrolytes. Potassium (K+) content of the cells plays a critical role in retention or excretion of potassium. The glomeruli of our kidneys excrete Potassium (K+) in glomerular filtrate and tubular epithelial cells also excrete Potassium (K+) by ion exchange in which Potassium (K+) of tubular cells is exchanged by Sodium (Na+) of glomerular filtrate. Re-absorption is controlled by proximal tubules whereas the excretion is controlled by distal tubules.

Low dietary intake, fever, trauma, or hemolysis leads to tissue catabolism in patients with anuria (no urine output) leading to release of more Potassium (K+) from the cells. In these patients Potassium (K+) concentration in blood may reach lethal level (more than 100 mEq/litre). Normal level of Potassium (K+) in serum is 5.5 mEq/litre. The clinical features of hyperkalemia (high level of Potassium in blood) could be mainly cardiac (bradycardia or arrhythmia) with significant changes in electrocardiogram (ECG). Potassium (K+) depletion may be renal or non-renal in origin and may be suspected when pronounced muscular weakness and lethargy is associated with electrolyte imbalance. Commonest cause of Potassium (K+) deficiency could be the uncontrolled use of diuretics for the treatment of congestive heart failure. Potassium (K+) deficiency leads to vacuolation of tubular epithelium in proximal tubules (known as clear cell nephropathy). The associated renal changes are reversible with correction in Potassium (K+) level in blood/serum. Aldosterone is Sodium (Na+) retaining adrenal corticoid secreted by adrenal cortex. Excessive secretion of this corticoid as in cases of adenoma of adrenal cortex may lead to increase in the level of Sodium (Na+) and extracellular fluid volume and altered function of Sodium pump. In usual Potassium (K+) losing nephropathies there is failure of hydrogen ion excretion in association with the failure of retention or conservation of Potassium (K+).

Hypercalcemia (high level of Calcium in blood) as seen in primary hyperparathyroidism, sarcoidosis, excessive vitamin D intake or idiopathic hypercalcemia of infants, may also result in renal damage. Hypercalcemia is also a feature of acute osteoporosis of multiple myeloma and matastatic carcinomatosis of bone. Hypercalcemia could be a lethal complication associated with sarcoidosis but may successfully be reversed with timely steroid therapy. The serum level of Calcium (Ca++) may return to normal in a few weeks but the reversal of renal insufficiency may take a year or longer. Calcium (Ca++) is retained in our body in the form of Calcium phosphate. The hormone like action of vitamin D during excessive intake, causes increased excretion of phosphorus in urine, unsaturation of serum Calcium phosphate, demineralization of bone leading to increased level of Calcium in blood and increased loss of Calcium in urine. Hypercalcemia could cause nephrocalcinosis leading to renal insufficiency.

Thursday, December 11, 2008

Renal Biopsy Procedure: Complications

Pathological lesions in affected kidneys of patients with renal disorder (kidney disease) could only be evaluated through histological, immunofluorescence and ultrastructural examination of renal biopsy. The renal biopsy (kidney biopsy) procedure as percutaneous needle biopsy was established long back in 1949 and has undergone a great refinement. At present, a large number of medical centers have been performing ultrasound guided percutaneous renal biopsy procedure for the diagnostic and prognostic evaluation of renal tissue. However, majority of the centers lack the facility of electron microscopy for ultrastructural examination of renal biopsies. Cases with microscopic hematuria (blood in urine) and hereditary nephropathies need ultrastructural examination of renal biopsy (kidney biopsy) for an accurate diagnosis. In expert hands the procedure is as safe as incision biopsy or percutaneous biopsy of liver, but post biopsy complications in rare cases could not be avoided. Hematuria (blood in urine) is a common complication and could rarely necessitate blood transfusion. There are 0.01 percent (1 in 10,000) chances of severe hemorrhage secondary to puncture leading to compulsive nephrectomy (surgical removal of kidney). Uncommon complications could be sepsis and hypertension due to perirenal hematoma. Renal biopsy (kidney biopsy) procedure is not advisable for patients with only one functional kidney.

Monday, December 8, 2008

CT Scanning And Its Side Effects

Computed Tomography (CT) scanning is used for assessing the health status of internal organs in a variety of conditions. X-ray computed tomography (CT) involves x-rays for the tomographic imaging. CT scanning promises a greater diagnostic accuracy in brain hemorrhage, tumors, arterial blockages, non-invasive angiography and status of internal organs in accidental cases. Though the harm associated with the medically necessary CT scan is below the unacceptable limits of radiation. A patient is exposed to 10 mSv radiation during a typical CT scan of chest whereas it gets only 0.02 mSv on a chest x-ray. The mSv is the symbol of milli-Seivert unit of radiation energy absorbed in tissues and 10 mSv stands for 1 Rem (Rad equivalent of man). Once or twice in life time, CT scan if required for medical diagnosis is not harmful but repeated CT scanning for the health assessment of asymptomatic individuals would jeopardize the safety limits. Age of an individual and frequency of exposure to radiation may affect the physical health and may lead to genetic mutations and cancer. Asymptomatic individuals approaching the commercial CT Scan Centers should be highlighted the side effects of CT scan. Such individuals should be referred back to their physicians for other medical examinations. In developed countries there are Radiation Safety Authorities to regulate the practice of such techniques. There are many conditions which could be diagnosed without CT scan. There is no evidence of any benefit of CT scanning for a lung disease or lesions of colon. If an asymptomatic or normal person with 40 years plus age receives a radiation dose of 10 mSv every year for five to 10 years, he/she will have 5 to 10 percent more chances of developing fatal cancer than without any exposure to radiation. CT scanning is very harmful for the pregnant females as the fetus should not be exposed to more than 5 mSv (0.5 Rem)radiation energy. As per ICRP guidelines, the maximum permissible exposure for the whole body in an adult is 20 mSv or 2 Rem/year. Avoid unwanted CT scanning to save your health and prolong your longevity.

Pulse As An Indicator Of Health And Disease

Radial pulse has been the technique of monitoring health status in humans from the time immemorial. The pioneer philosopher Heraclitus (540-475 BC) talked about two opposite forces; the fire or the heat and the water as essential components of life. These forces are always under rhythmic change under the influence of cosmic oscillations and influence our cardiovascular system. Medical practitioners generally assess the radial pulse on the wrist without any distinction of left or right wrist, but the Chinese concept makes distinction between the right and the left wrist and pulse palpation at the radial artery. There are fourteen radial pulses according to the Chinese system of medicine. There are three positions on the radial artery on each wrist. Position one is near the base of the thumb. On the left wrist there are six pulses; on each position one superficial and one deep pulse could be felt. On right wrist there are eight pulses; two pulses could be felt at position one and pulses at three levels (superficial, middle and deep) could be felt at the position number two and three. In addition to radial pulses, peripheral pulses could be felt at nine other points on human body. An experienced physician may fulfill the diagnostic needs of a patient through assessment of radial pulses only. Three levels of physical status; normal (standard), low activity or hypoactivity and high activity or hyperactivity could be assessed through analysis of the count and quality (length, sharpness and dullness) of the pulse.

The way to assess radial pulses as per the Chinese concept: Place the middle finger of your hand at the apophysis of radius (i.e. position-2) of the patient's wrist, the index and the ring fingers will automatically be placed on other two positions. Remember the position one is at the base of the thumb. Ideally the pulse on the right wrist of the patient should be assessed with the fingers of your right hand and on the left wrist with the fingers of your left hand. Develop an arbitrary scoring criterion of 1 to 7 for the quality of the pulse. Let score 4 represent the normal or standard, 3 to 1 represent hypoactivity or weakness and 5 to 7 represent the hyperactivity or over activity of some organs. Pulse count is taken as beats per minute whereas the qualitative parameters of pulse could be assessed in 3 to 5 minutes. It needs a lot of practice and experience to learn the Chinese concept of pulse evaluation. Please refer to the article "Pulse and pulse pressure" published on this blog in the month of July 2008 for additional information.